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Monthly Archives: July 2011

The Android operating system is on the rise. The last months I spent a lot of time testing mobile devices, especially the Android platform.l

One of the things that helped me a lot, is the ability to intercept SSL traffic on my Wireless Access Point. Therefore I set up a laptop with Burp, airbase and some iptables commands to redirect the traffic to the Burp proxy. In the Android browser I could simply accept the certificate warning, but for applications like the Google Android Market that’s not possible. Therefore I had to import the Burp CA into my Android device. As far as I know, this is only possible for rooted (and s-off) phones! The follwing things are necessary:

Except for the PortSwiggerCA, everything is included in this zip file. After adding the PortSwiggerCA, just execute the import-ca-and-upload.sh script and follow the instructions.

Happy intercepting!

Edit: Depending on which Android version you are running, Android now supports installing “Trusted Credentials”. It’s pretty simple: Download the Burp CA certificate (e.g. through the webinterface on http://burp/ or see below), rename cacert.der to cacert.crt, transfer it to your SD card (or /sdcard folder if you don’t have a physical card in your phone). Then go to “Settings – Security – Install from storage” and it should get recognised automatically. From now on you’ll get a very annoying message everytime you startup your phone (“Network may be monitored-by an unknown third party”) as if a custom CA is a bigger problem than the default CAs… To me all the default CAs are way worse “unknown third party”s. However, this setup is usually not working with your default Android browser and you might still need the steps above. Some apps work, but for example from Android 4.4 on Google uses certificate pinning on its Google server connections. Certificate pinning means you really have to apply hooking techniques to the app you are analysing.